1. Field of the Invention
The invention relates to a fiber optic scanner according to the preamble of patent claim 1, and to a range imaging camera (also denoted as 3D laser radar in the literature) in which such a fiber optic scanner is applied.
2. Discussion of Background Information
Fiber optic scanners are optomechanical units which serve to lead and deflect optical signals. In the case of a fiber optic line scanner, it is possible, for example, for the optical information falling onto a line to be converted into a sequence of optical pulses in a glass fiber.
The use of a fiber optic line scanner with a biaxial optical transceiver system for the purpose of producing 3D laser radar images is known, see, e.g., DE 39 42 770 C1 and/or its counterpart U.S. Pat. No. 5,225,876; and DE 39 42 771 C1 and/or its counterpart U.S. Pat. No. 5,109,459, the disclosures of which are expressly incorporated by reference herein in their entireties. The fiber optic scanner of the known systems includes separately from one another a transmit part for emitting laser light and a receive part, designed symmetrically therewith, for receiving the light reflected at the scene. The transmit part and receive part respectively include an array of a plurality of light guides whose first ends are arranged linearly and whose second ends are arranged annularly. The second ends of each array therefore form an annular structure at whose center the end of a central light guide is located. The central light guide is connected to a light source in the case of the transmit part, and to the detector in the case of the receive part. Moreover, a motor-driven rotating mirror is present in each case for transmit part and receive part in a fashion tilted with respect to its rotation axis. The rotating mirror is aligned in such a way that in the transmit part the laser light emerging from the central light guide is directed sequentially onto the circularly arranged ends of the light guide array. Conversely, upon receipt of the incoming light in the receive part the light emerging from the ends of the circular array is guided into the central light guide.
In order to be able to build a 3D laser radar more cost effectively, it is necessary to reduce the number of optical components, these being very costly, as a rule.